WO2007012593A1

WO2007012593A1 - Spot welding cap changer

Info

Publication number: WO2007012593A1
Application number: PCT/EP2006/064417
Authority: WO
Inventors: Werner Kaeseler
Original assignee: Werner Kaeseler
Priority date: 2005-07-28
Filing date: 2006-07-19
Publication date: 2007-02-01
Also published as: US20160271722A1; CA2993056C; US20200114462A1; EP1841559A1; KR20080033950A; US20130240489A1; PL1841559T3; US20170297139A1; JP2009502518A; CA2937276A1; US8742281B2; PT1841559E; ATE392979T1; BRPI0613980A2; DE502006000695D1; US10343233B2; CA2978755C; CA2614533C; US10065263B2; RU2008107575A

Abstract

The invention relates to a spot welding cap changer (1) with a cap puller (2) and two cap magazines (3, 3A), the cap puller (2) having a gripper (20) with spring-loaded, pivotable jaws (21, 22), which in response to a turning and axial pulling-off movement detaches a spot welding cap (K) of a pincer spot welding head introduced into it from a shaft of the pincer welding head in such a way that it is clamped to prevent it twisting, and the cap magazines (3, 3A) holding spot welding caps respectively in a round cap carrier (31) such that they are circularly arranged in a directed and oriented manner and are respectively transported individually one after the other into an access position against a stop (32) by an advancing force (P).

Description

Spot welding cap changer

The invention relates to a Punktschweißkappenwechsler with a cap puller and two cap magazines, wherein the cap extractor has a gripper with spring-loaded, pivoting jaws, which detaches an inserted into this spot welding a spot welding gun against rotation in a rotational and axial withdrawal movement of a welding tong shaft and wherein the Cap magazines point welding caps directed in each case in a cap carrier oriented and are each conveyed one by one to a stop in an access position by a feed force, from which they are axially attachable to the free welding tong shaft and pulled out with him.

Such a mechanical electrode cap changer is known from DE 102 22 248 Al. This has a two-piece, accessible from both sides, cap puller in a separate structure to the magazine.

Since the caps slip against a cap stop by gravity, the device can only be operated stationary in the vicinity of a mobile welding robot. A cap change on a stationary welding tongs, which in each case a component to be welded is supplied by a robot, is therefore not possible. The welding guns often have short, e.g. curved shanks, so that the all-round equipped with three jaws corresponding large cap puller is not to bring in a trigger position.

The object of the invention is a faster, safer change of the spot welding caps on both mobile and Stationary spot welding systems with short access path automatically allow.

The solution consists in that the cap extractor has two oppositely directed grippers with mutually pivotable, open at the end jaws with approximately parallel toothed gripping surfaces whose

Distance has a small undersize to a Schweißkappen- diameter, and the cap magazine each contains a cap carrier, which, driven by a spring box, with its feed force in each case one of the caps presses against the stop, and in the

Access position, an edge overlap the cap on one side overlaps.

Advantageous embodiments are specified in the subclaims.

In the new design, the cap puller and the magazine are mounted on a, preferably spring-mounted, carrier. In contrast to the previously known system, the new construction design not only enables use on welding robots, but also on stationary welding guns or systems.

Compared to the previously known clamping system with three jaws, the new cap-drawing guide allows shorter clamping and turning distances, thus significantly shorter times for loosening the caps. In addition, the smaller size results in a wider range of applications, e.g. on special tongs or very short curved shafts.

The two cap pullers are each open at the ends of the jaws and thus accessible for a cap. The jaws grip them directly by their undersize of their distance and solve the cap already at a rotation by an angle of about 30 - 60 °. As a result, a cap change is also extremely cramped space conditions possible. Since the two grippers are oriented in opposite directions, each one of them is available for access from the different sides in a clockwise rotation, so that no turning of the pliers is required, even if the Schweißzangenschäfte are kept screwed.

Furthermore, the round magazine is much more compact than the gravity straight magazine previously known construction. The spring drive allows it to be held and operated in any position.

The two axially parallel arranged round magazines also allow access to a short radial path to the engagement positions in the access openings. In an embodiment with a magazine lid this is moved so far when accessing so far that the edge cover releases the cap edge and the removal is possible. The example shows a radial shrinkage and axial access of the shafts in the magazine.

Both subdevices, the cap changer and the cap magazines, are mounted close to one another on a carrier and can thus be set up stationarily or fixedly or detachably mounted on a robot arm. In the first case, the welding robot changes the caps of its forceps, and in the second case, the robot changes the caps on the stationary forceps or equipment by means of the device. In this case, the changing device on the robot arm in a free space next to the gripper of the robot or slidably mounted on a guide rail permanently ready for use, or it is ready in a parking position, from which it is picked up by the gripper and used; one calls this change of pliers principle.

On the device cap sensors are advantageously arranged, which signal whether a cap is present or not. In addition, the level of the magazines is monitored. On This way it is ensured that after a cap change on the welding tong shaft a cap is present before the cooling water is switched on. Furthermore, it can thus check whether the old cap has been removed if no cap is reported when approaching the shaft.

The design of the cap magazine without lid holds the welding caps in an elastic cap carrier axially in a tight fit under pushing or pulling force.

Advantageous embodiments are shown in FIGS. 1 to 6.

Fig. 1 shows the overall device schematically in perspective;

Fig. 2 shows a transparent plan view of the cap puller; Figures 2A, 2B show detail enlargements of the gripping surfaces;

Fig. Fig. 3 shows a perspective of the cap puller;

Fig. 4 shows a cap magazine in perspective, closed, enlarged

Fig. 5 shows a cap magazine in perspective, opened, enlarged

Fig. 6 shows a top view of the magazine cover.

Fig. 1 shows a complete Punktschweißkappenwechsler 1, which is held displaceably on a support rail 5 on a robot arm. Alternatively, it is permanently installed with the mounting plate 50. At the free end of the mounting plate 50 of the two-sided fitted cap extractor 2 is screwed, wherein the two grippers 20 are each directed laterally opposite. There are drawn between the jaws 21, 22 withdrawn caps K, which are stiffened after peeling at the edge of a storage container in this.

Set back against the cap puller 2 each laterally offset a cap magazine 3, 3A mounted on the mounting plate 50, wherein the magazine cover 4 each directed laterally and the access openings 40 are aligned axially parallel to the withdrawn still held welding caps K, so that the Schweißzangenschäfte when changing caps only have to travel short distances.

Fig. 2 shows a plan view of the cap puller 2, which consists of very few parts. The grippers 20 each consist of a toothed fixed jaw 21 and a jaw pivotally mounted to this 22. The pivot joint 24 is formed by a U-shaped configuration of the movable jaw arm 25 moved behind the fixed jaw 21, whereby a located in the gripper 20 cap K is clamped at a rotation depending on the direction of rotation.

The initial pressing force of the jaws 20, 21 provides a spreading spring 26, e.g. is formed as a helical or spreading spring with splayed ends, which are each supported against a jaw arm 25.

On the inlet side, the grippers 20 on inlet slopes 27, 28. Of these, each extending approximately parallel gripping surfaces 23 which are provided with a respective oppositely directional toothing 29A, 29B, as Figs. 2A and 2B show in detail in detail. If no cap K is inserted into the gripper 20, then the distance A of the gripping surfaces 23 has a small undersize relative to the cap outer diameter D.

Fig. 3 illustrates that the spring 26 and the movable jaws 21, 22 and a jaw plate 62, on which the fixed jaws 21 are formed, between two cover plates 60, 61 are held. The jaw plate 62 has a corresponding recess in which the U-shaped jaw arms 25 have freedom of movement.

Fig. 4 shows a round cap magazine 3, which consists of a drum-like cap carrier 31 which is closed with a magazine cover 4, wherein a radial cutout is up to the rounded access opening 40, in which a welding cap K in the removal position to a stop edge 32 on the lid is pressed.

The lid 4 has at the rounding of the access opening 40 on a narrow edge cover 41 of the cap edge, to which an insertion bevel 42 connects stepwise to the ceiling top. To a version with a hinged lid 4 There is a slot 43 which is penetrated by an externally beveled hook 34 which holds the lid.

Opposite the access opening 40, a hinge 44 is formed with a slot 45 in the plane of extension of the lid, the pin 46 is held in a hinge support 47.

Fig. 5 shows the round magazine 3 with hinge open and equipped with a welding cap K in the holes 30 of the cap carrier 31, wherein the cap K protrudes by a few millimeters from it. In the center of the cap carrier 31 is fixedly mounted a schematically shown spring box 33 which carries the hook 34 radially displaceable. In the spring box 33 a prestressed spindle or coil spring is centrally arranged, one end of which are fixed to the spring box 33 and the other end to the cap carrier 31, so that the latter with a rotational force P in the direction of the stop 32 located on the magazine lid extends radially, is pressed.

The hook 34 extends in a plate-shaped manner in a diagonal guide slot on the lid of the spring box 33. From the hook 34 extends in the closed state, as shown here, held in the lid compression spring assembly 35 which is supported by a support pin 36 on the rounded hinge support 47 and presses the hook 34 in the closed position in which it engages over the lid 4 in the closed state and holds the edge cover 41 in the overlapping position, wherein the pin 46 is in the rear stop position in the slot 45, as shown in FIG. To open the lid 4, the hook 34 is pushed back by hand. Alternatively, the round magazine without hinge to open the lid can be performed. In that case, the lid is only slidably held, so that upon insertion of the forceps shank this over-pushes the lid on the slope 42 to release the edge overlap. Fig. 6 shows a plan view of the magazine cover 4, whose main contour consists of two semicircles with offset centers Ml, M2, wherein on the one hand the access opening 40 extends directed to the center and opposite the hinge 44 extends on the outside. The slot 43 in the cover 4 extends in the center region in the direction between the access opening 40 and the hinge 44. In this direction, the hook 34 in the lid and in the fixed spring box 33 is guided. The cover 4 is about 15 mm high and largely hollow and has a stiffening edge 48, which merges into the stop 32 and on the other hand in the hinge 44. The cover 4 is lowered to the insertion area on the insertion bevel 42 by about 5 mm. Internally, the cover surface guides the caps to the removal level when screwed into the stop position. A chamber 49, which receives the compression spring assembly 35 is shown in dashed lines.

The compact design of the cap puller with the magazines allows a considerable reduction in changeover times, for example, from 22 to 17 seconds, which corresponds to about 23%.

_IS J

LIST OF REFERENCE NUMBERS

1 spot welding cap changer

cap extractor

20 grippers

21, 22 Baking

23 gripping surfaces

24 swivel joint

25 cheek arm

26 spreading spring

27, 28 inlet slopes

29A, 29B teeth

3, 3A cap magazines

30 holes

31 cap carrier

32 stop

33 spring box

34 hooks

35 compression spring

36 support pins

4 magazine cover

40 access opening

41 edge coverage

42 insertion bevel on the lid

43 slot in the lid

44 hinge

45 slot in the hinge

46 cones

47 hinge supports

48 lid edge

49 compression spring chamber

5 carrier rail

50 mounting plates

60, 61 cover plates

62 baking plate A jaw clearance

D cap outside diameter

K cap

P feed force

M1, M2 semicircle centers

Claims

claims

1. Spot weld cap changer (1) with a cap puller (2) and two cap magazines (3, 3A), wherein the cap puller (2) has a gripper (20) with spring-loaded, pivotable jaws (21, 22), which introduced into this spot welding cap (K) a spot welding pliers against rotation detracting from a rotary and axial withdrawal movement of a welding collet shank detaches and wherein the cap magazines (3, 3A) Spotschweißkappen each oriented in a cap carrier (31) and oriented by a feed force (P) in each case individually to a stop

(32) are conveyed into an access position, from which they are axially attachable to the free welding tong and with him pulled out, characterized in that the cap extractor (2) two oppositely directed gripper (20) each with each other pivotable, open at the end jaws (21 , 22) with approximately parallel toothed gripping surfaces (23), the distance (A) has a small undersize to a welding cap diameter (DK), and the cap magazine (3, 3A) each containing a cap carrier (31), the, of a spring box (33) driven, with its feed force (P) in each case one of the caps (K) presses against the stop, and in the access position, an edge cover (41) engages over the cap (K) on one side.

2. Punktschweißkappenwechsler according to claim 1, characterized in that in each case one of the jaws (21) of the associated gripper (20) is fixedly formed on a jaw plate and the relevant movable jaw (22) is formed on a U-shaped jaw arm (25), which is mounted with a pivot joint (24) beyond the fixed jaw (21).

3. Punktschweißkappenwechsler according to claim 2, characterized in that between the two movable jaw arms (25) z. B. a prestressed spreading spring (26) is arranged.

4. Punktschweißkappenwechsler according to any one of the preceding claims, characterized in that the jaws (21, 22) wear inlet slopes (27, 28).

5. Punktschweißkappenwechsler according to claim 4, characterized in that the gripping surfaces (23) each carry an asymmetrical toothing (29 A, 29 B), which is directed opposite to the two parallel jaws (21, 22).

6. Punktschweißkappenwechsler according to claim 3, characterized in that the jaw arms (25), the spreading spring (26) and the jaw plate (62) between cover plates (60, 61) are held.

7. Punktschweißkappenwechsler according to claim 1, characterized in that the spring box (33) includes a spiral or spiral spring, the ends of which on the one hand to the spring box

(33) and on the other hand on the cap carrier (31) are fixed.

8. Punktschweißkappenwechsler according to claim 1, characterized in that a magazine cover (4) is biased by a spring (35) in the direction of the access opening (40), so that the edge cover (41) engages over a cap edge in its stop position.

9. Punktschweißkappenwechsler according to claim 8, characterized in that on the spring box (33) a hook (34) is held spring-loaded displaceable, which engages the Magazazindeckel (4) closed and holds over.

10. Punktschweißkappenwechsler according to claim 8 or 9, characterized in that the magazine cover (4) on a Hinge support (47) is hinged, which is the access opening (40) opposite.

11. Punktschweißkappenwechsler according to claim 10, characterized in that the magazine cover (4) on the hinge support (47) is displaced in a slot (45).

12. Punktschweißkappenwechsler according to any one of the preceding claims, characterized in that the magazine cover (4) carries a stiffening lid edge (48), on the one hand in the edge cover (41) and on the other hand in a hinge (44) passes.

13. Punktschweißkappenwechsler according to any one of the preceding claims, characterized in that the cap puller (2) is mounted with front protruding grippers (20) on a mounting plate (50) and on the back offset the cap magazine (3, 3A) are mounted.

14. Punktschweißkappenwechsler according to claim 13, characterized in that the access openings (40) of the cap magazines (3, 3A) are each directed to different sides of the mounting plate (50) and project beyond this laterally.

15. Punktschweißkappenwechsler according to claim 13 or 14, characterized in that the mounting plate (50) on a support rail (5) is held displaceably guided, which is mounted on a robot arm or permanently installed.

16. Punktschweißkappenwechsler according to one of the preceding claims, characterized in that on the cap magazines

(3, 3A) Sensors are arranged, which signal a control device when only a predetermined residual amount of spot welding caps (K) in the respective cap carrier (31) is in stock.